Summary/Abstract ? Animal Experiment and Statistics Core The long-term objectives of this Program Project are to elucidate host and viral mechanisms that tilt the interaction of herpes simplex virus (HSV) and neurons either towards lytic infection or towards latency. HSV latency is the most fascinating biological property of the virus and its most important clinical feature, and understanding HSV latency may lead to new therapies or even a cure for this widespread pathogen. All three projects use mice to study latency. The first aim of the animal experiment and statistics core is to provide animals to the investigators in these projects. A second aim is to ensure uniform practices in the inoculation, treatment, and handling of mice and mouse tissues for Projects 1, 2, and 3, so that results from one project can be directly compared to those from the other projects. Standard protocols have been created that include initial experiments using a single wild type strain of virus and mutants derived from it, and a common mouse strain for studies that do not require inbred strains. Subsequent studies use other virus and mouse strains to ensure broader applicability. Specific methods for minimizing pain and discomfort, including anesthesia and euthanasia also ensure uniformity. Importantly, the third aim of the core is to provide assistance and guidance in planning of mouse experiments so that they are appropriately powered, and to help with statistical analyses of data generated by the experiments. Thus, the core is a high-quality cost-effective means of rigorously testing HSV-1 wild type and mutant viruses in vivo for parameters of latency and reactivation and of providing trigeminal ganglia tissue for analyses and for cultured neurons for in vitro latency studies. By having centralized oversight, the Program avoids duplication of experiments and unnecessary use of animals, and ensures rigor and reproducibility.